Out of the six possible combinations shown in the tree, three of them have tails. Tails,1 tails,2 and tails,3 are the three possible solutions with tails. So the answer is C.

7 0

3 years ago

3) Solve each equation using the quadratic formula. Show<br> a. x2 – 3x – 10 = 0

Naya [18.7K]

Answer:

Step-by-step explanation:

The quadratic formula of a quadratic equation

$ax^2+bx+c=0\\\\\text{If}\ b^2-4ac>0\ \text{then the equation has two solutions}\ x=\dfrac{-b\pm\sqrt{b^2-4ac}}{2a}$

$\text{If}\ b^2-4ac=0\ \text{then the equation has one solution}\ x=\dfrac{-b}{2a}$

$\text{If}\ b^2-4ac$

We have:

$x^2-3x-10=0\to a=1,\ b=-3,\ c=-10\\\\b^2-4ac=(-3)^2-4(1)(-10)=9+40=49>0\\\\x=\dfrac{-(-3)\pm\sqrt{49}}{2(1)}=\dfrac{3\pm7}{2}\\\\x=\dfrac{3-7}{2}=\dfrac{-4}{2}=-2\\or\\x=\dfrac{3+7}{2}=\dfrac{10}{2}=5$